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Study confirms 'Angelina Jolie' effect

Angelina Jolie's announcement detailing her decision to undergo a double mastectomy to reduce the risk of breast cancer influenced hundreds of women to do the same, an Australian study has confirmed.

Analysis of hospital discharge data from New York State and NSW between 2004 - 2014 shows there was nearly a doubling of women to undergo a risk-reducing mastectomy.

In total, 1,808 and 487 women aged 16 to 80 years-old underwent RRM in New York and NSW, respectively.

According to the study, published in journal Health Services Research, there were an average of 3.3 bimonthly RRM cases per one million women in New York before Jolie's announcement; 20 months after the announcement there were an average of 6.3 bimonthly RRM cases per one million women.

Rates of risk-reducing mastectomy in NSW were relatively similar, according to the paper.

Lead author, Professor Louisa Joram - Foundation Director of the Centre for Big Data Research in Health at UNSW - says the data confirms the 'Angelina Jolie' effect.

There was already, however, an underlying trend that showed RRM cases were on the rise, Prof Jorm noted.

"But over the entire 40 months there was pretty much a doubling in both New York and NSW," she said.

The epidemiologist says the findings show the power celebrities have to influence the healthcare decisions of the general public.

"There are lots of other examples of this and people probably remember the 'Kylie (Minogue) effect' from back in 2005, in that case there was evidence that a lot of younger women, women who are not recommended to have mammography, went and had it," said Prof Jorm.

A woman can be at very high risk of developing breast cancer if she has a strong family history of breast and/or ovarian cancer and carries the BRCA2 gene mutation.

Prof Jorm says the decision to have preventative surgery is a very personal one and it's important that balanced, evidence-based information is made available when celebrities announced personal health news.

"A feature of the way Jolie's decision was reported is that it was focused very much on the risk reduction and the benefits and less focused on the pros and cons and that its very much an individual decision for every woman," she said.

"So, it may have encouraged people who may have made another decision without that publicity to take the decision to have the risk-reducing mastectomy but we don't know that, all we have is the data on the rates of the procedure."